Yeah, MIPS is probably the best example and did get some uptake. But the big vendors mostly went their own way. Although I was involved in that history to a degree, I'm not entirely sure why history played out the way it did.
Well...any history will attract a torrent of nitpicking, so this is my extremely reductist take. Motorola, IBM & Apple decided to join up on a common HW platform called "PReP" which was POWER/PPC based, so Motorola dumped 88k to play ball with that. PReP was a flash in the pan, but PPC briefly shone as Apples processor, and is still around in various forms (mostly embedded now, but POWER still ships in volume). Similar trajectory with MIPS. Clipper was never going to be a big player; it was a niche within a niche. SPARC, HPPA & Alpha got steamrolled by much cheaper, performance competitive x86 derived processors. In the end, most volume customers said "can it run my software fast and cheap" and by sometime in the 90s that was clearly an x86 (unless your name was "Apple", but that's a different history).
